By Gary Wolf, Wired Magazine, April 2008
The winter sun sets in mid-afternoon in Kolobrzeg, Poland, but the early twilight does not deter people from taking their regular outdoor promenade. Bundled up in parkas with fur-trimmed hoods, strolling hand in mittened hand along the edge of the Baltic Sea, off-season tourists from Germany stop openmouthed when they see a tall, well-built, nearly naked man running up and down the sand.
"Kalt? Kalt?" one of them calls out. The man gives a polite but vague answer, then turns and dives into the waves. After swimming back and forth in the 40-degree water for a few minutes, he emerges from the surf and jogs briefly along the shore. The wind is strong, but the man makes no move to get dressed.
Piotr Wozniak's quest for anonymity has been successful. Nobody along this string of little beach resorts recognizes him as the inventor of a technique to turn people into geniuses. A portion of this technique, embodied in a software program called SuperMemo, has enthusiastic users around the world. They apply it mainly to learning languages, and it's popular among people for whom fluency is a necessity - students from Poland or other poor countries aiming to score well enough on English-language exams to study abroad.
SuperMemo is based on the insight that there is an ideal moment to practice what you've learned. Practice too soon and you waste your time. Practice too late and you've forgotten the material and have to relearn it. The right time to practice is just at the moment you're about to forget. Unfortunately, this moment is different for every person and each bit of information.
Fortunately, human forgetting follows a pattern. We forget exponentially. A graph of our likelihood of getting the correct answer on a quiz sweeps quickly downward over time and then levels off. This pattern has long been known to cognitive psychology, but it has been difficult to put to practical use. It's too complex for us to employ with our naked brains.
Twenty years ago, Wozniak realized that computers could easily calculate the moment of forgetting if he could discover the right algorithm. SuperMemo is the result of his research. It predicts the future state of a person's memory and schedules information reviews at the optimal time.
SuperMemo is a program that keeps track of discrete bits of information you've learned and want to retain. Your chance of recalling a given word when you need it declines over time according to a predictable pattern. SuperMemo tracks this so-called forgetting curve and reminds you to rehearse your knowledge when your chance of recalling it has dropped to, say, 90 percent. When you first learn a new vocabulary word, your chance of recalling it will drop quickly. But after SuperMemo reminds you of the word, the rate of forgetting levels out. The program tracks this new decline and waits longer to quiz you the next time.
In the late 1800s, a German scientist named Hermann Ebbinghaus made up lists of nonsense syllables and measured how long it took to forget and then relearn them. In experiments of breathtaking rigor and tedium, Ebbinghaus practiced and recited from memory 2.5 nonsense syllables a second, then rested for a bit and started again. Finally, in 1885, he published a monograph called Memory: A Contribution to Experimental Psychology. The book became the founding classic of a new discipline.
Ebbinghaus discovered many lawlike regularities of mental life. He was the first to draw a learning curve. Among his original observations was an account of a strange phenomenon: the spacing effect.
Ebbinghaus showed that it's possible to dramatically improve learning by correctly spacing practice sessions. The efficiencies created by precise spacing are so large, and the improvement in performance so predictable, that from nearly the moment Ebbinghaus described the spacing effect, psychologists have been urging educators to use it to accelerate human progress.
The spacing effect is "one of the most remarkable phenomena to emerge from laboratory research on learning," the psychologist Frank Dempster wrote in 1988, in a paper titled "The Spacing Effect: A Case Study in the Failure to Apply the Results of Psychological Research." How would computer scientists feel if people continued to use slide rules for engineering calculations? Psychologists who studied the spacing effect thought they possessed a solution to a problem that had frustrated humankind since before written language: how to remember what's been learned.
As a student at the Poznan University of Technology in western Poland in the 1980s, Wozniak was overwhelmed by the sheer number of things he was expected to learn. He wasn't just trying to pass his exams; he was trying to learn. He couldn't help noticing that within a few months of completing a class, only a fraction of the knowledge he had so painfully acquired remained in his mind.
So he created an analog database, with each entry consisting of a question and answer on a piece of paper. Every time he reviewed a word, phrase, or fact, he meticulously noted the date and marked whether he had forgotten it. By 1984, Wozniak's database contained 3,000 English words and phrases and 1,400 facts culled from biology, each with a complete repetition history.
According to Wozniak's first calculations, success was impossible. The problem wasn't learning the material; it was retaining it. He found that 40 percent of his English vocabulary vanished over time. Sixty percent of his biology answers evaporated. Using some simple calculations, he figured out that with his normal method of study, it would require two hours of practice every day to learn and retain a modest English vocabulary of 15,000 words.
As Wozniak later wrote: "The process of increasing the size of my databases gradually progressed at the cost of knowledge retention." In other words, as his list grew, so did his forgetting. He was climbing a mountain of loose gravel and making less and less progress at each step.
"The people who criticize memorization - how happy would they be to spell out every letter of every word they read?" asks Robert Bjork, chair of UCLA's psychology department and one of the most eminent memory researchers. "You can't escape memorization. There is an initial process of learning the names of things. That's a stage we all go through. It's all the more important to go through it rapidly."
Long-term memory, the Bjorks said, can be characterized by two components: retrieval strength and storage strength. Retrieval strength measures how likely you are to recall something right now. Storage strength measures how deeply the memory is rooted.
Some memories may have high storage strength but low retrieval strength. Take an old address or phone number. Try to think of it; you may feel that it's gone. But a single reminder could be enough to restore it for months or years. Conversely, some memories have high retrieval strength but low storage strength - easily accessible now but likely forgotten in days.
The amount of storage strength you gain from practice is inversely correlated with the current retrieval strength. In other words, the harder you have to work to get the right answer, the more the answer is sealed in memory. Precisely those things that seem to signal we're learning well - easy performance on drills, fluency during a lesson - are misleading when it comes to predicting whether we will remember it in the future.
Robert Bjork, working with Thomas Landauer of Bell Labs, published results involving nearly 700 undergraduate students. They were looking for the optimal moment to rehearse something so that it would later be remembered. Their results were impressive: The best time to study something is at the moment you are about to forget it.
Obviously, computers were the answer. What was needed was not an academic psychologist but a tinkerer, somebody with a lot of time on his hands, a talent for mathematics, and a strangely literal temperament that made him think he should actually recall the things he learned.
All of Wozniak's early work was done on paper. "We had a single mainframe of Polish-Russian design, with punch cards," he recalls. The personal computer revolution was already far along in the US by the time Wozniak managed to get his hands on an Amstrad PC 1512, imported through quasi-legal means from Hamburg, Germany. With this he was able to compute the difficulty of any fact or study item and adjust the predicted forgetting curve for every item and user.
After the collapse of Polish communism, Wozniak and some fellow students formed a company, SuperMemo World. By 1995, their program became the first Polish product shown at Comdex in Las Vegas.
The reason the inventor of SuperMemo pursues extreme anonymity is not because he's paranoid but because he wants to avoid random interruptions to a long-running experiment he's conducting on himself. Wozniak is a kind of algorithmic man. He's exploring what it's like to live in strict obedience to reason.
His days are blocked into distinct periods: a creative period, a reading and studying period, an exercise period, an eating period, a resting period, and then a second creative period. He doesn't get up at a regular hour and is passionate against alarm clocks.
Wozniak has invented a way to apply his learning system to unstructured information from books and articles, winnowing written material down to discrete chunks that can be memorized, and then scheduling them for efficient learning. He calls it incremental reading, and it has come to dominate his intellectual life.
"Once you get the snippets you need," Wozniak says, "your books disappear. They gradually evaporate. They have been translated into knowledge."
Wozniak wrote a checklist describing how to become a genius. His advice was straightforward yet strangely terrible: You must clarify your goals, gain knowledge through spaced repetition, preserve health, work steadily, minimize stress, refuse interruption, and never resist sleep when tired. This should lead to radically improved intelligence and creativity. The only cost: turning your back on every convention of social life.
It is a severe prescription. And yet, when linked to genuine rewards, even the chilliest of systems can have a certain visceral appeal. By projecting the achievement of extreme memory back along the forgetting curve, by provably linking the distant future - when we will know so much - to the few minutes we devote to studying today, Wozniak has found a way to condition his temperament along with his memory. He is making the future noticeable. He is trying not just to learn many things but to warm the process of learning itself with a draft of utopian ecstasy.
Originally published in Wired Magazine, April 21, 2008
